The prior art engine (U.S. Pat. No. 5,402,755), proposed by Waissi, is an internal combustion engine with opposed and aligned cylinders, called here the Waissi Engine. The Waissi Engine consists of at least one pair of aligned and opposed cylinders wherein a reciprocating double-headed piston is slidably mounted, and in which the double-headed piston axis intersects perpendicularly with the axis of a driveshaft. The reciprocating motion of the double-headed piston is transmitted to the driveshaft by a rotating crankdisk. The crankdisk is rigidly and off-centered mounted to the driveshaft, which is rotably mounted to a crankcase. The double-headed piston has two slots perpendicularly through its axis, one of which is to allow for a rotating movement of the crankdisk, and the other, to allow for the rotation of the driveshaft. The prior art further discloses that the double headed piston may be assembled from multiple components or parts. The lubrication between the piston slot bearing surface and the crankdisk outer perimeter bearing surface of the Waissi Engine is by oil splash. This arrangement allows metal to metal contact resulting into high unacceptable friction between the piston slot wall bearing surfaces and the crankdisk outer annular bearing surface. The crankdisk outer perimeter forms a circle.
In conventional prior art engines (V-, in-line, opposed) the metal to metal contact between the piston connecting-rod big-end and the crankshaft is avoided by creating hydrodynamic lubrication conditions in an oil film of the connecting-rod to crankshaft bearing. It is therefore, and in order to reduce friction and wear, highly desirable to create similar hydrodynamic lubrication conditions in the piston to crankdisk contact surface of the Waissi Engine, and, in particular, to provide for crankdisk rotation under hydrodynamic conditions.
The prior art improvement (SAE SP-1108, Paper No. 950090, Futuristic Concepts in Engines and Components, pp. 61-64, (1995)) to the Waissi Engine proposes to reduce friction between the crankdisk annular bearing surface and piston internal bearing surfaces by a special bearing ring. Within this improvement the outer perimeter surface of the crankdisk acts as a bearing and slides inside the bearing ring. The crankdisk has a diameter and annular perimeter design that fits tightly but slidably inside the bearing ring. The bearing ring, with a diameter that fits in-between the piston slot bearing surfaces (or inside the piston slot), is intended to roll or slide on the piston bearing surface. The crankdisk perimeter and surface design correspond the conventional engine crankshaft—piston rod journal design to provide for hydrodynamic lubrication.
However, as summarized above, while the prior art addresses the crankdisk perimeter and surface design and need for providing for hydrodynamic conditions, the prior art clearly fails to describe the required design of the bearing ring for the Waissi Engine such that the design would provide for a possible and feasible assembly, that the assembled bearing ring would stay in its designed place when the crankdisk rotates, and that the assembled bearing ring would provide for improved hydrodynamic conditions, and thereby would reduce friction and wear to aid the crankdisk movement. The prior art does also not address alternative crankdisk—piston assembly designs that utilize roller- or ball bearings in place of the above bearing ring.